Among the various fishing gears employed for

pelagic schooling fishes along the Kerala coast,

seines are the most efficient. Contribution of ring

seine to total marine fish landings of Kerala has

steadily increased since its introduction during the

early eighties. It was 21.4 % in the nineties rising to

36.7 % during the period 2000-2004 and contributing

more than 50 % since then. In recent years, about

90 % of the oil sardine and about 60 % of the

mackerel landed in Kerala were caught in ring

seines. Ring seines were introduced during the early

eighties by traditional fishers of Alappuzha District

which became highly successful

Abdussamad, E M

Ganga, U

Gireesh, R

Koya, K P Said

Prakasan, D

CMFRI Digital Repository

Mar. Fish. Infor. Serv., T & E Ser., No. 225, 2015 3Ring seine fishery of Kerala: An overviewE. M. Abdussamad1, U. Ganga1, K. P. Said Koya2, D. Prakasan1 and R. Gireesh11ICAR - Central Marine Fisheries Research Institute, Kochi2Calicut Research Centre of ICAR - Central Marine Fisheries Research Institute, Kozhikodeboats with an OAL of upto 20 m, locally known asThanguvallom, with a crew of 25 or more fishermen.The capitalization continued in the sector byusing three 25 hp OB engines which increased tothree 40 hp engines and became commonplace. Forthis, the fibreglass coated Kettuvallam with atransom stem made of marine plywood withfacilities to fit 3 outboard engines conveniently wasintroduced. However, the craft had no fish holdfacility and this led to introduction of carrier boatsystem for quick transport of catch to landingcentres, while the main unit continued fishing. Inearly 2000, the introduction of inboard dieselengines (IB ring seiners) was a significantdevelopment and the trend has continued withincrease in size of the craft and engine power. Largeboats called “Thanguvallom” of OAL between 19.8- 25.9 m, breadth 3.6 - 4.5 m and depth 2.1 - 3.4 mpowered by inboard diesel engine became popular.Initially, most of these units used 180-225 hp IBengines. Recently, vessels with 30 m (100 feet) OAL,fitted with Chinese made high speed IB engines ofover 400 hp are operating. With the introduction oflarge nets, purse line winches were fitted in thesevessels to facilitate quick closing and hauling of thegear. Medium sized boats of 10.7 - 13.7 m OAL knownas Vallom, fitted with OB engine of 25 hp and aboveare being used as carrier vessels by these fishingvessels.Till the middle of 1960s different kinds of boatseines made up of cotton and hemp fibres, popularlyknown as Ayilakollivala / Ayilachalavala /Adakkamkollivala were used. After that a new boatseine called Pattenkolli made of nylon fibre wasintroduced, with much smaller size mesh, thatdominated the fishery till mid 1980s. Ring seinesfirst introduced in 1982 were broadly grouped intotwo categories, the small meshed Choodavala/Among the various fishing gears employed forpelagic schooling fishes along the Kerala coast,seines are the most efficient. Contribution of ringseine to total marine fish landings of Kerala hassteadily increased since its introduction during theearly eighties. It was 21.4 % in the nineties rising to36.7 % during the period 2000-2004 and contributingmore than 50 % since then. In recent years, about90 % of the oil sardine and about 60 % of themackerel landed in Kerala were caught in ringseines. Ring seines were introduced during the earlyeighties by traditional fishers of Alappuzha Districtwhich became highly successful. The new fishingmethod spread to entire Central and Northern Keralaand Kollam District towards south,  replacing almostall the prevailing fishing gears for pelagic resources.However, due to consistent opposition to ring seinesfrom traditional fishers they have not beenintroduced in Thiruvananthapuram district tilldate.Craft and gear charactersDuring the initial phase of introduction, ringseines were operated from small dug-out canoes of6.5 to 9.8 m overall length (OAL) which weremanually propelled using oars. Since more time andenergy was  required to reach the fishing groundsand search for shoals, the fishing operations wererestricted to a distance within 10 nautical miles(nmi). Since 1984 outboard engines were introducedfor the propulsion of crafts. Initially 7 hp engineswere used which were replaced by 25 hp engineswhich helped them to reach the fishing grounds andback very quickly. By 1987, almost all country craftswere fitted with out-board (OB) engines. Later,larger vessels with OAL between 13.7-18.3 m knownas Vallom were widely introduced with fishingactivities extending to areas beyond 10 nmi. Thesewere gradually replaced with large sized plank builtMar. Fish. Infor. Serv., T & E Ser., No. 225, 20154Discovala and large meshed Thanguvala/Ranivala.The Choodavala/Discovala is relatively smaller insize below 250 m in length, 30-70 m depth, with 8-12 mm mesh webbing and targets anchovies andperchlets. The Thanguvala that mainly targets oilsardine and mackerel generally is 800 to 1000 m inlength, 80 to 100 m in breadth with 22 mm meshand weighs between 1.5 to 2 tonnes (t).  Severalmodifications have been made by the fishermen inthe design of the gear to enhance its performance.However, tempo of gear modifications has beenmuch slower compared to that of crafts.Ring seine net being loaded on to an IBRS unitRing seine nets operated by IBRS units being mendedOwnership PatternIn the ring seine sector, ownership of the fishingunits is either individual or collective. The individualownership is restricted to smaller crafts up to 40feet OAL, which are generally non-motorised orCarrier boats landing at Thottappally Fisheries Harbour,Alappuzha Districtfitted with outboard motors (OBM). For larger sizedcrafts, the ownership is collective with the unitbeing owned by a group of fishermen (shareholders).Fishing operationThe gear is operated in near shore area withinthe depth zone of 10-50 m and up to 12 nauticalmiles (nmi) from shore. Fishing units move todifferent areas in search of fish shoals based on seaconditions, wind and current patterns, movementof seabirds and/or sea mammals which are used asindicators of presence of fish shoals. Earlier, surfaceshoals were identified by experienced fishers fromthe shoal behaviour. Currently, SONAR with digitaldisplay is being widely used to locate and identifythe shoals. If very big shoals are located, informationis communicated to other units at sea or on shoreand accordingly more units move to the fishingground.Shoals are encircled with the net towed atmaximum speed to minimize fish escape. Thetrapped fishes are concentrated close to the craftat bunt portion and net hauled to mother boat. Ifthe shoal is very big, partial harvest with scoop netsis done. Catch by small vessels is transporteddirectly by the fishing units themselves to thelanding centres which may return to the sameground to fish until the shoals are exhausted. Thusin a day, two to three operations are carried out bysmall vessels, depending on distance to the ground.In the case of larger crafts, while the vessel remainsin the fishing ground and continues fishing, one orMar. Fish. Infor. Serv., T & E Ser., No. 225, 2015 5more carrier vessels associated with it are used totransport catches to the shore. Attack by dolphins and puffer fishes are commonduring ring-seining usually during the time of haulingthe catch on-board. This leads to heavy loss to thefishers through net damage and fish escape. It alsoincreases labour and causes loss of time.  Suchincidents are more frequent in recent days, afterextension of fishing activities to deeper waters. Theissue is being addressed by operating Dolphin WallNet (DWN) locally known as “Pannivala” around thering seine. Once the fish shoal is encircled by thering seine, it is surrounded by DWN operated froma dinghy/carrier vessel. DWN is made up of 300-400 mm polyethylene webbing of 1.5 mm twine and1000 – 1500 m length framed with float line andsteel rings hanging from the lower edge. Two typesof DWN are in use, one with conventional plasticfloat with selvedge for reducing entanglement offloats to the webbings, other with thermocol blocksand oil cans as floats and without selvedges.Trends in fishing effortSince its introduction in 1982, effort by ringseines have increased steadily.  Inboard ring seines(IBRS) first introduced in 1999 became more populardue to high catch rate and return and resulted inits wide adoption subseqently. The upward trend ineffort by outboard ring seines units (OBRS) continuedtill 2008 after which it started declining. Total effortin active fishing time also shows similar trend (Figs.1 & 2). The upward trend in effort from 2002 byinboard ring seines also continued till 2012 anddeclined thereafter due to low catch and catchrates, which made their operations economicallyunviable.Ring seine catch characteristicsRing seine, which is the major gear operatedalong Kerala coast contributed about 51 % of thetotal annual landings  of the state during 2008-2014.Since its introduction, there was steady increase infish landings till early nineties followed by a steepfall in production in 1994  due to the drastic declineof the oil sardine fishery. Following the revival ofthe oil sardine stock, the production reached anall-time high of nearly 4 lakh t in 2012. Peak landingby outboard sector occurred in 2003 after which ithas fluctuated over the years. Landings by inboardsector registered steep increase during 2009-2012period after which it has declined sharply (Fig. 3).Carrier boat with catch of anchoviesFig. 1. Fishing effort (in units )by OBRS and IBRS unitsalong the Kerala coast during 2001-2013Fig. 2. Fishing effort (in hours) by OBRS and IBRS unitsalong the Kerala coast during 2001-2013Mar. Fish. Infor. Serv., T & E Ser., No. 225, 20156Oil sardine (Sardinella longiceps), Indianmackerel (Rastrelliger kanagurta) and white baits(stolephorus spp.) are the most dominant resourcesaccounting for about 84% of the ring seine catch.Other resources caught are the lesser sardines,clupeids, coastal tunas, seerfishes, ribbonfishes,carangids and penaeid prawns (Table 1). Oil sardineis the mainstay of the marine fish landings in Keralawith average landings during 2011-2015 being 2.24lakh t. Ring seine is the major gear used for fishingoil sardine and contributed to 94% of the total oilsardine caught in the state during the period. Oilsardine in the fishery was supported by 45-220 mmsize fishes with bulk formed by 100-170 mm sizegroups. During 2011-2014 period oil sardines below140 mm total length (TL) which is the Size at FirstMaturity (Lm-the length at which approximately fiftypercent of the fishes are mature) formed about 66%of the estimated numbers landed while juvenilesbelow Minimum Legal Size (MLS) of 100 mm formedonly 12 %. Indian mackerel is the second dominantspecies exploited by ring seine. The average annuallanding of mackerel in the ring seine during 2011-2015 was 0.28 lakh t which formed 9.8% of the totalring seine landings of Kerala. The size groups thatsupported the fishery was 105-260 mm with a meansize of 179 mm.Anchovies contributed 11.3% of the total ringseine catch during the period. Fishery was supportedby more than 10 species of the family Engraulidae.Lesser sardines constituted 3.8 % of the ring seinecatch and generally formed a major portion of theTable 1. Major resources landed by ring seines along theKerala coast and their percentage contributionduring 2010-14Species/group Mechanised Out boardring seine (%) ring seine (%)Major resourcesOil sardine 63.77 62.01Other sardines 5.75 2.89Mackerel 17.84 6.10Stolephorus spp. 2.22 10.58Coastal tunas 2.56 0.02Scads 2.41 0.52Minor resourcesRays 0.003 0Wolf herring 0 0.05Thryssa spp. 1.68 4.17Belonids 0.01 0.32Croakers 0.15 1.09Ribbon fishes 0.34 0.01Horse mackerel 0.23 0.06Silver bellies 0.01 0.26Big-jawed jumper 0 0.08Barracuda 0 0.01Sliver pomfret 0 0.03Mullets 0 0.01Soles 0.04 0.44Prawns 0.42 3.95Crabs 0 0.03Squids 0.04 0Other clupeids 1.80 3.70Other perches 0.05 2.05Other carangids 0.45 1.52Fig. 3. Catch trend in IBRS and OBRS units off Keralacoast during 2001 - 2014catch by ring seines operated in the  southerndistricts. Among lesser sardines, Sardinella gibbosa,S. albella and S. fimbriata dominated the catch.Catch of juveniles of other large pelagics like seerfishes, tuna and carangids also occurs occasionally.The juveniles of sardines and anchovies were morepredominant during June-September period andthat of mackerel throughout the monsoon and postMar. Fish. Infor. Serv., T & E Ser., No. 225, 2015 7monsoon months (June-November). Catch ofjuvenile fishes off Kerala coast has becomes a majorconcern among the scientific community as well asfishers during recent years.SummaryRing seines fishery, since its introduction hasregistered steady growth both in terms of fishingeffort and yield till 2012. Thereafter, due todeclining catches, mainly of oil sardine, economicreturns were affected adversely. Recently, theseriously dwindled catches  of oil sardine along theKerala coast has rendered the ringseine operationseconomically unviable. Though the oil sardine catchin the gear was supported mainly by immaturefishes, major share of the catch was above thedeclared MLS of 100 mm total length. Moreover,spawning stock biomass was also high at 30-38%during 2010-2014, which is sufficient to sustain stockand fishery of this resilient species.The El Ninowhich set towards the end of 2012, intensifiedduring successive years with peak impact in 2014and 2015 as indicated by the Oceanic Nino Index(ONI). The impact of El Nino appeared to be highlyadverse for oil sardine. The prevailing environmentalconditions along the west coast especially alongKerala coast was not conducive for immediaterecovery of the oil sardine fishery as indicated bythe poorly fed conditions and stunted growth.Apparently unfavorable environmental conditionshave resulted in migration of the oil sardine to areaswith more favourable ecological conditions. Earlierstudies suggest that oil sardine will  come back whenimpact of El Nino subsides. The recent crisis infishery due to drastic decline of the oil sardinefishery off Kerala coast as well as the declarationof the MLS For 14 commercially important speciesincluding oil sardine and mackerel through agovernment notification (GO(P) No. 40/15/F& PDdated 24th July 2015) facilitated by scientific inputsof ICAR-CMFRI has increased awareness amongringseine fishers on the adverse effects of juvenilefishing (Ramachandran and Mohamed, 2015Economic & Political Weekly, Vol. 1., No. 35).The Central Institute of Fisheries Technology(CIFT) had recommended only about 300 units ofring seines for the Kerala coast but a study by SouthIndian Federation of Fishermen Societies (SIFFS) in1998 estimated 1636 ringseine units operating withan estimated 2277 numbers of nets. The overalldimensions of the gear had also grown three to fourtimes from the design introduced by CIFT (Edwin etal., 2010, Proc. National Seminar on Conservationand Sustainability of coastal living resources inIndia, SOFTI (India), CIFT, Cochin). Even now, fishersthemselves are continuing to make changes in designand size of the gear according to their vesselcapacity to get better catches. Studies haveindicated that simple doubling of the gear lengthincreases the effective fishing area by almost 4 fold.A combination of increased gear and vessel size,engine power etc. will therefore enhance the fishingcapability several fold leading to high fishingpressure on the stock. Hence, strict measures toregulate the excessive fishing pressure is required.Depending on the distance to fishing ground andavailability of shoals, small ring-seine units areundertaking several fishing trips in a day. Largervessel units on the other hand remain in the seaand continue fishing till the shoals are fully tapped.These intense fishing practices prevent escape ofeven a small part of the shoal and raise concerns ofsustainability. It is advisable to enforce regulatorymeasures such as number of fishing trips in a day orseason, number of carrier boats and trips, enginehorsepower or even quantum of fish that can becaught and landed by the ring seine units to ensuresustainable exploitation of the resources. As a largenumber of fishermen depend on ring seine fishingfor their livelihood, these conservation andregulatory measures need to be developed inconsultation with the stakeholders.

Ring seine fishery of Kerala: An overview

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Ring seine fishery of Kerala: An overview

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